Reaction vessel and method for the handling thereof

ABSTRACT

A cuvette for an automatic analyzing apparatus according to the invention includes at least two positions, for each position pair one separating wall connecting the positions, and brackets, which are at the outermost positions and which guide the cuvette into a curved shape. In a handling method of a cuvette according to the invention a cuvette is transported from its brackets to an incubator and bent into a curved shape. In the method the cuvette is then loaded into an opening of the incubator, in which opening it remains by its own spring back factor, until the cuvette is removed from the opening after the analysis.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of co-pending application Ser. No.12/993,710 filed on Nov. 19, 2010, which is the national phase of PCTInternational Application No. PCT/FI2009/050450 filed on May 27, 2009,and which claims priority to Application No. 20085509 filed in theFinland on May 28, 2008. The entire contents of all of the aboveapplications are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a new type of a reaction vessel, i.e. acuvette, for usage in automatic analyzers and to a cuvette incubationmethod. More precisely, the present invention relates to a cuvette andan incubation method according to the preambles of the independentclaims.

2. Description of Background Art

As known, disposable and reusable cuvettes have been used in automaticanalyzers as individual cuvettes or as sets of cuvettes. Cuvettes arevessels into which a sample to be analyzed and possible other substancesto be used in the test are portioned out for the analysis. Reusablecuvettes are cleaned between the analyses, whereas disposable cuvettesare designed to receive only one sample during their life span. Thecleaning of the cuvettes between the tests is laborious due to theproperties of the cleaning products and to the potentionally dangeroussubstance to be removed. Thus, especially when performing a large amountof tests, disposable cuvettes are favored, which are delivered to wastetreatment after use and it is certain enough that they are clean atleast when taken into use.

Disposable cuvettes are known that there are manufactured as acontinuous chain of cuvettes, which can be bent about two axes into aspiral shape and which are adapted to be moved, wrapped around themoving orbicular bodies of the analyzer. Likewise, columns of cuvettesare already known, which can be moved from cuvette specific protrusions,between which conveying members, such as toothed belts, are adapted topenetrate. As known, the attachment of the cuvette or the set ofcuvettes to a testing apparatus is performed with external shapedconnection of the cuvette, such as pin couplings, and such that thereceiving means of the testing apparatus comprising flexible separatingwalls hold the cuvette in place.

However, the prior art has some disadvantages. The cuvettes according toprior art are usually suitable to be used in only one application,whereby they have not been suited to be used in several different typesof analyzers and incubators. The known cuvette-incubator-pairs haveincluded a plurality of maneuvers and precision mechanics and thus, notbeing particularly robust in structure nor in operation. In addition,said pairs are typically test-oriented, which means that only analysesof a specific test, typically a photometric analysis, is performed inone test sequence. This is why there have been gratuitous delays inreceiving patient or sample specific results. Likewise, the abundance ofmaneuvers has resulted in that the sample-carrying cuvettes beingexposed to several contacts, which has worn their outer surfaces. Insome cases excess wear has have impaired the optical properties of theclear vessels. The wear and tear is especially intensive when thevessels are being washed, which is disadvantageous only with reusablecuvettes.

SUMMARY AND OBJECTS OF THE INVENTION

An object of an embodiment of the present invention is to solve at leastpart of the aforementioned problems and to provide an improved cuvetteand a handling method thereof.

A cuvette according to the invention comprises two positions, which areconnected by a separating wall, and at least one bracket at theoutermost positions being able to support the cuvette and yieldelastically when pressed inward. The separating walls between thecuvette positions allow for the elastic bending of the cuvette about itsvertical axis. More precisely, the cuvette according to the present ininvention is characterized by what has been stated in the characterizingportion of the independent apparatus claim.

In a cuvette handling method according to the present invention acuvette is transported from its brackets to an incubator and it is bentinto a curved shape after which the cuvette is loaded into an incubatoropening in which it remains by means of its own spring back factor.Hereafter the sample to be analyzed is portioned out into the samplespace of the position of the cuvette, it is analyzed while being in theincubator, and the cuvette is finally removed from the incubatoropening. More precisely, the handling method according to the presentinvention is characterized by what has been stated in the characterizingportion of the independent method claim.

Considerable advantages are gained with the aid of the invention. Due tothe brackets and elasticity along the vertical axis, the cuvetteaccording to the present invention can advantageously be used inapparatuses that automatically analyze samples. Due to the suitableyielding properties the cuvette may be transported to an incubator andloaded therein without scratching the vulnerable optical surfaces of thecuvette. Likewise, the brackets contribute to bending the cuvettetightly into the exact bow for it to be throughout its length incontinuous contact with the walls of the receiving incubator opening.With the aid of the brackets is also easy to place and center thecuvette into the receiving incubator opening.

The loading and ejecting movement of the handling method comprises onlyone direction and movement, whereby the method is robust and reliable.Due to the yielding properties in relation to the vertical axis of thecuvette, neither excess shaped connections nor precision mechanics isrequired. For the same reason one type of cuvette can be used in variousdifferent incubators resulting in considerable cost savings for theuser. In addition to the previously mentioned advantages, thesufficiently long brackets and the separating walls separating thepositions of the cuvette according to the present invention guaranteethat there is an even temperature distribution during the test sequencein the cuvette. Thus, the heat conducting from one sample space toanother does not compromise the accuracy and reliability of the test.

Further scope of applicability of the present invention will becomeapparent from the detailed description given hereinafter. However, itshould be understood that the detailed description and specific example,while indicating preferred embodiments of the invention, are given byway of illustration only, since various changes and modifications withinthe spirit and scope of the invention will become apparent to thoseskilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description given hereinbelow and the accompanying drawingswhich are given by way of illustration only, and thus are not limitativeof the present invention, and wherein:

FIG. 1 shows an isometric view of a cuvette with 10 positions.

FIG. 2 shows a side view of the cuvette of FIG. 1.

FIG. 3 shows an elevated view of the cuvette of FIG. 1.

FIG. 4 shows an incubator and a cuvette, which can to be adapted to itsorbicular body.

FIG. 5 shows the loading funnel of the incubator of FIG. 4.

FIG. 6 shows a cuvette according to another embodiment of the presentinvention equipped with single projection brackets.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As illustrated in FIG. 1, the cuvette 10 comprises positions 20, whichare in line next to each other. By a cuvette 10 is meant in this contexta sample-receiving member with at least one position 20 for receivingthe sample and for storage at least during analysis. The position 20 isa tubular vessel wherein a confined sample space 28 for a sample to beanalyzed is formed and which is limited by the walls of the vessel. Theposition 20 has, according to one embodiment, a rounded quadrangularshaped cross-section and is generally shaped such that the sides of theopening of the sample space 28 are considerably shorter than the depththereof. The sample space 28 can also have another shape. In thiscontext, the direction of the longest side of the sample space 28 of theposition 20, i.e. the depth, is called the vertical axis.Correspondingly by a horizontal axis is meant the Cartesian axesorthogonal to the vertical axis.

The cuvette 10 has, according to one embodiment of the invention, 10positions, which are separated from each other by separating walls 22.The separating wall 22 is an isthmus-like connecting part between twopositions 20. As illustrated in FIGS. 1 and 2, the separating wall 22 isessentially in the middle of the narrow faces of the parallel positions20 such that the separating wall 22 extends from the upper edge of thecuvette 10 to about half way of the side face of the positions 20. Inother words, the separating wall 22 does not connect the positions 20over their whole length, but only along their upper half. The basic ideaof the separating wall 22 is to be a connecting element, which does notcontribute to transfer heat from position to another, but on thecontrary isolates the positions 20 from each other. Thus, the heatconducted between the positions 20 remains as minimal as possible, whichimproves the accuracy of the analysis.

One essential feature of the separating wall 22 is its elasticity. Asillustrated in FIG. 3, the separating walls 22 are rather thin comparedto the walls of positions 20, especially compared to their verticallength. Due to the profile of the separating walls 22 and the elasticmaterial thereof, the cuvette 10 can be bent about its vertical axis,i.e. about the axis directed orthogonally upward from the plane of FIG.3. By elastic material is in this context meant a material, which iselastic enough to cope with intended deformations it experiences. Thematerial of the cuvette 10 and especially of the separating wall 22 isselected such that the construction may be exposed to bending, wherebythe separating walls 22 experience elastic deformation, due to whichelasticity the cuvette 10 tends to react against the bending thustautening itself back to its original position. Thus, the elasticity ofseparating walls 22 is essential, because the structure must remainelastic also under bending strain for reasons explained later on.Besides elasticity the material must have suitable optical properties atleast as positions 20 are concerned. Plastic, especially acryl, is forexample a sufficiently elastic and suitable bright material.Alternatively the cuvette 10 may be manufactured of more than onematerial. In this case, parts requiring yielding properties, such asbrackets 24 and separating walls 22, can be made of essentially elasticmaterial, such as polyurethane, and parts requiring optical properties,such as positions 20, can be made of material having good opticalproperties, such as acryl. Furthermore, upon material selection, it ispossible to favor materials that have good optical characteristics. Forexample, a material can be favored, which is elastic in its application,but of which material made cuvette 10 is not adapted to recover entirelyafter the bending, but the separating walls 22 of the cuvette 10 wouldexperience partial plastic deformation. Thus, the cuvette 10 wouldremain slightly bent after use, which would indicate that the producthas been used and reuse would be prohibited.

As illustrated in FIGS. 1, 2 and 3, the outermost positions 20 areequipped with brackets 24. According to one embodiment of the invention,the bracket 24 consists of two protrusions, which are considerablyshorter in the direction of the vertical axis of the cuvette 10 than thecuvette 10 and which are rather fragile in regard to their wallthickness. The protrusions of the bracket 24 are oriented outward fromthe upper part of the outer edge of the outermost positions 20 such thatthe protrusions curve towards each other. By the outer edge of theposition 20 is meant the side edge of either of the outermost position20 not having a separating wall 22. Correspondingly, the directionoriented outward is the horizontal direction oriented from theseparating wall 22 toward the outer edge of the position 20.

The brackets 24 are, as the separating walls 22, of elastic material,due to which they too endure elastically the bending about their longestside. The yielding properties of the brackets 24 are the best in theorientation direction of the cuvette 10. Thus, the protrusions of thebrackets 24 persist the compression toward the position 20. Theelasticity of the brackets 24 is essential, because the structure mustremain elastic under compression due to reasons explained later on. Itis likewise important that the inward compressed brackets 24 do not bendinto contact with the position 20 under compression, but keep a distancebetween the fixation and the position 20, whereby there is no thermalconduction between its outer edge and the fixation. If there were tooccur thermal conduction between the fixation and the outermostpositions 20 of the cuvette 10, they would receive more heat than therest of the positions 20. In such a case, an uneven temperaturedistribution would be formed into the cuvette 10, which would impair theaccuracy of the measurement.

As is apparent from FIGS. 1 and 2, the positions 20 of the cuvette 10may be equipped with screens 26 suitable for optical analysis. Accordingto one embodiment of the present invention, the screen 26 is a part inthe lower end of the position 20, which has been made transparent andwhich has suitable optical properties for analysis. In addition, thescreen 26 must be large enough for the analyzing ray to fit reliablyacross the position 20 and for the small aligning errors caused by themechanical parts of the analyzing apparatus not to make the measurementmore difficult. It is thus possible to perform analyses based on opticalexamination such that the sample remains in the sample space 28 of theposition 20, whereby the number of maneuvers and sample transfers issmall as possible. In order to avoid excess wear and tear of the screen26, its sensitive surface can be manufactured such that it is slightlydeeper than the rest of the face of the position 20. Said cavityprovides protection from the majority of scratching contacts, wherebywearing occurring during the packaging phase, for example, is directedtoward the side faces of the positions 20 instead of toward the screens26.

As illustrated in FIG. 4, the cuvette 10 is especially suitable to beused in an automatic incubator 30. According to one preferredembodiment, the incubator 30 comprises a heated disc 32 into the outerperimeter of which openings 34 for receiving the cuvettes 10 have beenmade. The disc 32 is fitted with a bearing in the middle wherein meansfor rotation (not shown) are arranged, with the aid of which the disc 32can be rotated a desired amount in a desired direction. The rotationmeans can, for example, comprise a servomotor, which has excellentpositioning accuracy but which is considerably expensive. The powertransmission of the incubator 30 can be arranged with sufficientaccuracy by fitting the disc directly on the axle of a cost efficientand sufficiently accurate stepping motor, whereby the transmission hasonly a necessary amount of moving parts and as few sources of play aspossible. The incubator 30 further comprises, in connection with thedisc 32, a loading track 38, along which cuvettes 10 are brought to beloaded into the opening 34 of the disc 32. The loading track 38 is inits simplest embodiment a channel having a U-shaped cross-section andwhose horizontal edge is essentially as wide as the lower edge of thecuvette 10 and whose vertical edges are essentially lower than thecuvette 10. Thus the cuvette 10 may be transported from its brackets 24along the loading track 38 such that the brackets 24 of the cuvette 10are placed on top of the vertical edges of the loading track 38, wherebythe lower edges of the positions 20 are at a distance from the bottom ofthe loading track 38. The gap between the lower edge of the positions 20and the bottom of the loading track 38 makes it possible for the loweredge of the position 20 not to grind the bottom of the loading track 38and thus preventing scratching.

To the loading track 38 side of the disc 32 a loading funnel 40 has beenfitted, through which cuvettes 10 are loaded into the openings 34 of thedisc 32. The loading is performed by using a press 36, the lower edge ofwhich is adapted to press the cuvette 10 into the loading funnel 40, inwhich it is adapted to acquire a shape allowing it to fit into theopening 34 and to proceed into the opening 34. The curvature of theopening 34 conforms to the curvature of the disc 32. Due to of theelasticity of the cuvette 10, it may be used with various discs 32 andfurther openings 34 with different curvature radii. As is apparent fromFIG. 5, the loading funnel 40 is shaped such that a cuvette 10 passingthrough it assumes a curved shape able to fit into the opening 34. Thecuvette 10 receiving edge 42 of the loading funnel 40 is convex whenviewed from the entering direction of the cuvette, whereby a cuvette 10pressed against it bends into a shape conforming to the perimeter of thedisc 32. The curvature of the receiving edge 42 of the loading funnel 40can be planar, i.e. constant, or it can vary in the horizontaldirection, whereby the receiving edge 42 is planar at its upper edge andprogressively convex when viewed lower. Thus the cuvette 10 is adaptedto bend gradually conforming to the receiving edge 42, whereas the face42 being evenly curvaceous, the cuvette 10 is adapted to bendimmediately to the curve shape desired. The loading funnel 40 is alsoequipped with brackets 24 with receiving side edges 44, against whoseinner edge the brackets 24 are pressed. Thus, the cuvette 10 is inintensive contact with the loading funnel 40 only at the brackets 24,whereby they receive the wear and scratching resulting from bending.Therefore the fragile surfaces of the cuvette 10, such as screens 26 andtheir surroundings, avoid erosion. Furthermore, the side edges 44 of theloading funnel are equipped with guides 46 securing that the brackets 24of the cuvette 10 are pressed against the inner faces of the side edges44. When the cuvette 10 is pressed against the lower edge of the loadingfunnel 40, its brackets 24 are pressed in and the separating walls 22are bent, whereby the cuvette 10 is tightly curved against the receivingface 42 of the loading funnel 40 and ready to be loaded equally tightlyin to the opening 34 of the disc 32. With the aid of the brackets 24 thecuvette 10 is placed and centers itself automatically into the opening34 even though the disc 32 should not be in the exactly correctposition. The cuvette 10 can certainly have a different constructionachieving the qualities described above. For example, a cuvette 10illustrated in FIG. 7 could be a possible embodiment, but only if itwould result in above described qualities. Likewise, the cuvette 10could also be straight and not adapted to assume a curved shape, wherebythe cuvette 10 would be designed to remain in a corresponding straightopening 34 only due to the elastic properties of its brackets.

The path of the press 36 is so long that the upper edge of the cuvette10 is at a desired height when it is pressed in to the opening 36.Accordingly, the pressing depth of the press 36, which may be programmedto suit the application, determines the vertical alignment. As above,the when loading the cuvette 10 into the opening 34 its brackets 24receive the most abrasion, which the other surfaces avoid. As thecuvette 10 is in the opening 34 of the incubator 30, the fluid or othersubstance to be analyzed can be distributed into the sample spaces 28.It is to be noted that the cuvette 10 may be designed for incubators 30with discs 32 and further openings 34 of various sizes, as describedabove. Thus, a cuvette 10 of a certain size can be used in variousapplications, which provides considerably cost savings while the varietyof cuvettes is minimal.

The disc 32 is heated for maintaining as favorable analyzing conditionsas possible, due to which heat is conducted to positions 20 and furtherto sample spaces 28 through the side face of the opening 34. With theaid of separating walls 22 the positions 20 are separated from eachother not causing temperature distortion with their preheat betweenadjacent positions 20. An even temperature is further improved bysufficiently prominent brackets 24, which isolate the outer edges of theouter positions 20 of the cuvette 10 from the heated faces of theopening 34.

The analyzing apparatuses have been arranged around the incubator 30such that there is no need to remove the cuvette 10 from the opening 34during testing. For example, optical tests may be performed directlythrough the screen 26 of the position 20. Therefore, the position 20 ofthe cuvette 10 loaded from the loading track 28 into the opening 34 ofthe incubator 30 is adapted to receive substances from severalmanipulators by changing the position of the disc 32. The analyzingprocedure can in this case be arranged such that the reagent isportioned out into the sample space 28 of the position 20 by means if areagent dispenser, which retrieves the substance from a reagent storage.The dispensing of the reagent requires that the disc 32 of the incubator30 has been rotated into a correct position such that the correctposition 20 is in a reagent receiving position. The basic idea of thearrangement is that the sample is moved in the cuvette 10, the positionof which is changed by rotating the disc 32 of the incubator, wherebythe number of maneuvers and directions is as small as possible. Thesamples for their part are dispensed in a similar manner by means of asample dispenser, which retrieves the substance from a sample storage.The reagent and sample can be mixed by rotating the disc 32 into thevicinity of a mixer and by starting the mixer. The contents of theposition 20 can be analyzed optically as described above and, forexample, with a manipulating analyzer adapted to suck the sample intoits test space and to measure its voltage compared to a reference value.The sectioning and programming of the test sequences and maneuvers ispreviously known.

When the tests performed to all used positions 20 are completed, thecuvette 10 can be ejected from the opening 34 such that the press 36having performed the loading pushes the cuvette 10 out of the opening 34into a separate receiving bin or into the waste opening 50 of theincubator 30. Alternatively, the press 36 can load a new cuvette 10through the loading funnel 40 into the opening 34, whereby the usedcuvette 10 is pushed out by the new one into a separate waste bin orinto the waste opening 50 of the incubator 30.

The invention being thus described, it will be obvious that the same maybe varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the invention, and all suchmodifications as would be obvious to one skilled in the art are intendedto be included within the scope of the following claims.

1. A cuvette for an automatic incubator, which cuvette comprises: atleast two positions comprising an optically transparent screen at a sidethereof for optical analysis, the positions only being connected over aportion of a vertical length thereof by a separating wall the number ofwhich is totally one less than a number of the positions, the separatingwall being of elastic material, including polyurethane or acryl, toallow elastic deformation of the cuvette about a vertical axis thereof,and brackets in outermost positions, being adapted to guide the cuvetteinto a curved shape about the vertical axis.
 2. A cuvette according toclaim 1 wherein the brackets are elastically flexible when pressed in.3. A cuvette according to claim 2, wherein the separating wall connectsparallel positions along at most half of a side face of the cuvette toimprove an even temperature distribution.
 4. A cuvette according toclaim 1, wherein the cuvette is made of a material with essentially goodoptical and elastic properties, including acryl.
 5. A cuvette accordingto claim 1, wherein the cuvette is made of two materials.
 6. A cuvetteaccording to claim 5, wherein the materials are mutually differentpolymers so that the first material has essentially good opticalproperties and the second material has essentially good elasticproperties.
 7. A cuvette according to claim 6, wherein the positions aremade of the first material and the separating walls or the brackets, orboth are made of the second material.
 8. A cuvette according to claim 6,wherein the first material is acryl.
 9. A cuvette according to claim 6,wherein the second material is polyurethane.
 10. A cuvette according toclaim 2, wherein the separating walls allow the cuvette to bendelastically about the vertical axis thereof.
 11. A cuvette according toclaim 3, wherein the separating wall connects parallel positions alongat most half of the side face of the cuvette to improve an eventemperature distribution.
 12. A cuvette according to claim 2, whereinthe brackets comprise flexible protrusions, which curve outwards andtowards each other from upper edges of the outer comers of the outermostpositions, whereby the brackets are adapted to be elastic in a positionorientation direction, and to be torsionally rigid in a verticaldirection.
 13. A cuvette according to claim 3, wherein the bracketscomprise flexible protrusions, which curve outwards and towards eachother from upper edges of the outer comers of the outermost positions,whereby the brackets are adapted to be elastic in a position orientationdirection, and to be torsionally rigid in a vertical direction.
 14. Acuvette according to claim 4, wherein the brackets comprise flexibleprotrusions, which curve outwards and towards each other from upperedges of the outer comers of the outermost positions, whereby thebrackets are adapted to be elastic in a position orientation direction,and to be torsionally rigid in a vertical direction.
 15. A cuvetteaccording to claim 2, wherein the cuvette is made of a material withessentially good optical and elastic properties, including acryl.